RNA epigenetic regulation of cancer metabolism

建议的研究是为了探索一种新的表观遗传学机制来控制代谢。 在癌细胞中重新编程。假尿苷酸化是一种常见的人类mRNA的表观遗传修饰 是由伪尿苷合成酶(PUS)家族催化的，该家族通过碱基- 专一性异构化。信使核糖核酸假尿酸的分子和功能后果很差 明白了。一个主要的障碍是缺乏合适的和强大的实验模型来研究功能和 信使核糖核酸假尿酸的调控。我们通过关注Pus家族来解决这个问题 癌症中的酶。我们的初步研究表明，其中一种酶PUS7的表达 由癌基因MYC和MYCN转录上调，这两个基因通常在不同的 人类癌症的类型。PUS7的高表达促进癌细胞的增殖和肿瘤的发生。 PUS7的一个关键下游靶点是ATF4，它是应激反应和细胞新陈代谢的主要调节因子， 它也是MYCN重新编程细胞代谢以维持癌细胞增殖的目标。 PUS7可在ATF4基因的特定位点催化假尿酸，并上调ATF4的表达。基座 根据这些发现，我们假设PUS7是MYC/MYCN在癌症代谢中的效应因子 通过假尿路激活ATF4基因的表达来重编程。我们进一步 假设PUS7-ATF4轴在应激诱导的代谢控制中起关键作用 重新编程。这项拟议的研究将检验这些假设。目标1的研究将集中在 PUS7依赖的ATF4基因假尿酸在应激模型系统中的生物学意义 回应。我们将定义依赖于PUS7的ATF4 mRNA的分子机制 假性尿毒症增加ATF4的表达(目标1.1)。我们将确定PUS7依赖的ATF4 mRNA 假尿路是由应力信号调节的，是ATF4的应力诱导所必需的(目标1.2)。我们会 确定PUS7是否通过调节ATF4的表达来控制应激诱导的代谢重编程(目标1.3)。 目的2研究PUS7依赖的ATF4基因假尿酸与肿瘤的相关性 使用MYC/MYCN癌细胞系和肿瘤模型。我们将确定PUS7是否为MYC/MYCN的效应器 在代谢重新编程中(目标2.1)。我们将确定PUS7介导的ATF4 mRNA 假尿路由MYC/MYCN调控，是MYC驱动肿瘤的表观遗传学事件 发展(目标2.2)。我们将调查PUS7基因敲除是否会在 MYC/MYCN驱动的可用于癌症治疗的肿瘤(Aim 2.3)。成功完成这项工作 该项目将阐明依赖PUS7的mRNA的生物学功能和与癌症的相关性 假尿酸，这可能会被用来更好地治疗癌症。

The proposed research is to investigate a new epigenetic mechanism for the control of metabolic reprogramming in cancer cells. Pseudouridylation is a common epigenetic modification of human mRNA, which is catalyzed by the family of pseudouridine synthases (PUS) that convert uridine to pseudouridine via base- specific isomerization. The molecular and functional consequences of mRNA pseudouridylation are poorly understood. A major barrier is the lack of suitable and robust experimental models to study the function and regulation of mRNA pseudouridylation. We approached this problem by focusing on the PUS family of enzymes in cancer. Our preliminary studies revealed that the expression of one of the enzymes, PUS7, is transcriptionally upregulated by the oncogenes MYC and MYCN, which are commonly activated in various types of human cancers. Increased expression of PUS7 promotes cancer cell proliferation and tumorigenesis. A key downstream target of PUS7 is ATF4, a master regulator of stress responses and cellular metabolism, which is also targeted by MYCN in reprogramming cellular metabolism to sustain cancer cell proliferation. PUS7 catalyzes pseudouridylation at specific sites in ATF4 mRNA and upregulates ATF4 expression. Based on these findings, we hypothesize that PUS7 is an effector of MYC/MYCN in cancer metabolic reprogramming by boosting ATF4 expression via ATF4 mRNA pseudouridylation. We further hypothesize that this PUS7-ATF4 axis has a key role in the control of stress-induced metabolic reprogramming. The proposed research will test these hypotheses. Aim 1 studies will be focused on the biological relevance of PUS7-dependent ATF4 mRNA pseudouridylation in the model system of stress responses. We will define the molecular mechanism by which PUS7-dependent ATF4 mRNA pseudouridylation increases ATF4 expression (Aim 1.1). We will determine if PUS7-dependent ATF4 mRNA pseudouridylation is regulated by stress signals and is required for stress induction of ATF4 (Aim 1.2). We will determine if PUS7 controls stress-induced metabolic reprogramming by regulating ATF4 expression (Aim 1.3). Aim 2 studies will be focused on the cancer relevance of PUS7-dependent ATF4 mRNA pseudouridylation using MYC/MYCN cancer cell lines and tumor models. We will determine if PUS7 is an effector of MYC/MYCN in metabolic reprogramming (Aim 2.1). We will determine whether PUS7-mediated ATF4 mRNA pseudouridylation is regulated by MYC/MYCN and is an epigenetic event during MYC-driven tumor development (Aim 2.2). We will investigate if PUS7 knockdown creates a metabolic vulnerability in MYC/MYCN-driven tumors that could be exploited for cancer therapy (Aim 2.3). Successful completion of this project will shed light on the biological function and cancer relevance of PUS7-dependent mRNA pseudouridylation, which might be exploited for better cancer treatment.